When we blink, the flow of visual information between the world and one's retina is temporarily interrupted. In that instant of blinking, visual stimulation from the external world is lost for 150-400 milliseconds (ms or msecs). As a result, the average adult in the course of a single waking day will spend approximately 44 minutes with his or her eyelids closed missing visual information. During those moments, a variety of neural systems encompassing movement of the oculomotor muscles, activity in supplementary and frontal eye fields, and widespread activity in visual, parietal, and prefrontal cortical areas work together to suppress the actual visual signal of an occluding eyelid. These systems create the illusion of perceptual continuity, but if new visual information is presented in that instant of blinking, it will be missed.
During the collection of eye movement data, eye-blinks have been traditionally regarded as noise or artifact data and are generally deemed useless. However, blinking also relates to cognitive states beyond mere physiological function. It is also generally known that individuals remain largely unaware of their blinking, although blinking may be generally related to both explicit and implicit attentional pauses in task content.
Identification and quantification of a person's engagement with a visual stimulus can provide insights for many different fields. In cognitive and behavioral testing, as for autism, attention deficit hyperactivity disorder (ADHD), developmental disabilities, and other cognitive conditions, measuring how engaged a viewer is with specific types of visual (or audible) content can provide a biomarker of disease/disorder state, disease/disorder progression, and/or treatment response. For instance, children with developmental disabilities, which affect 1 in 10 within the general population, show delayed acquisition of speech and language skills. A measure of a child's engagement with speech and language cues (e.g., level of engagement with talking faces or communication gestures, which are precursors to language acquisition) can aid in the diagnostic identification of a child with developmental disabilities at a much earlier age than diagnosis of such disabilities conventionally occurs.
In another example, in commercial industries, one of the main concerns for many marketing companies is measuring the effectiveness of various marketing campaigns. Traditional approaches to determining visual marketing campaign effectiveness include conducting consumer surveys and questionnaires, analyzing sales numbers, social media “buzz”, etc. However, marketing companies would benefit from having a mechanism to determine directly from viewer behavior, without secondhand reporting or surveys, the effectiveness of a visual marketing campaign by measuring the level of a viewer's or group of viewers' engagement to that marketing campaign during test trials prior to releasing the campaign or during the actual campaign. In another example, developers of visual teaching aids may also benefit from having a measure of student engagement levels during the development phase of the teaching aids. Other industries could benefit from measuring indicators of engagement to visual stimuli, such as video game developers, flying and driving simulator developers, etc.
Therefore, there is a long-felt but otherwise unresolved need for a system and method that can assess and measure viewer engagement. Moreover, there is a need to measure engagement with certain visual and/or auditory stimuli, such as movies, television shows, marketing campaigns, print ads, web pages, emergency videos, teaching aids, even physical environments and objects, etc. in order to enable optimization thereof. Further, there is an additional need for a system and method to use measures of viewer engagement as biomarkers for assessing disease/disorder state, disease/disorder progression, and/or treatment response in conditions such as autism, ADHD, schizophrenia, bipolar disorder, depression, and others that effect engagement with circumscribed content.